(a) Field of the Invention
This invention relates to novel 1,2,6-thiadiazine-3,5-dione-1,1-dioxides (malonyl sulfamides) and to the use of 1,2,6-thiadiazine-3,5-dione-1,1-dioxides as accelerators for peroxides polymerization of ethylenically unsaturated compounds, such as methacrylic acid or acrylic acid compounds. The invention is of particular utility in formation of temporary dental crowns and bridges.
(b) State of the Art
U.S. Pat. No. 2,956,997 describes 1,2,6,-thiadiazine-3,5-dione-1,1-dioxides (malonyl sulfamides) in which the substituent at one cyclic nitrogen is an aromatic or araliphatic hydrocarbon radical. The compounds described in the patent are characterized as having pharmaceutical properties, in particular antiphlogistic, antipyretic and analgesic activity, and therefore as being suited for treating rheumatic diseases.
German Auslegeschrift No. 1,495,520 described a process for polymerizing acrylic acid esters, methacrylic acid esters, acrylonitrile, vinyl acetate or styrene in the presence of organic peroxides in which barbituric acids, inter alia, may be used as accelerators. In addition a compound containing ionically bonded halogen and/or a copper compound may be used. The process described is used, for example, in the preparation of impression compositions, filling compositions, dentures, investments and fixatives in the fields of dentistry and dental technology.